Is it possible to make always on display in series 4 through IOS new version

Always On is a series 5 feature only.

ASC - Late 2012 Mac mini, macOS 10.15.2; Watch, series 5 GPS/cellular, watchOS 6.1.1; iPad Air 2, ipadOS 13.3; iPhone 8+, iOS 13.3; TV 4th Gen, tvOS 12.4.1;  HomePods, audioOS 13.3 and Airport Express w/ Airplay 2

Because the Series 5 does it in hardware. The Series 5 drops the refresh rate down to once a second, which is very power conservative. The Series 4 cannot do this. Changing the software to just keep the display on would quickly drain your battery.